Method of and apparatus for treating pulp stock



G. KNOPP Sept. 5, 1933.

METHOD OF A ND APPARATUS FOR TREATING PULP STOCK Filed June 4, 1930 2Sheets-Sheet l R O T N E V m Ga ml Kno M y M ATTORNEY? Sept, 5, KNQPP.

METHOD OF AND APPARATUS FOR TREATING PULP STOCK 2 Sheets-Sheet 2 FiledJune 4, 1930 l h u u.

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INVENTOR Gama! fino a a W, M M ATTORNEYJ Patented Sept. 5, 1933 UNITEDSTATES PATENT OFFICE METHOD or AND APPARATUS FOR TREATING PULP STOCKApplication June 4,1930, Serial No. 459,215, and in Germany July 11,1929 Claims.

My invention relates to a method of and apparatus for treating anysuitable kind of pulp stock or other fibrous material destined to beutilized in the manufacture of paper, board, cardboard,

5 or otherwise as may be desirable.

My invention, in one of its prominent phases, involves an arrangementfor disintegrating or separating bundles of pulp stock into fibres orfor greatly diminishing the size of such bundles m of pulp stock.

My invention also relates to an'arrangement or system for cleaning ortreating suitable pulp stock to remove impurities therefrom.

Various other objects, advantages and characteristics of my inventionwill become apparent from the following description taken in connectionwith the accompanying drawings.

.My invention resides in the method, system,

apparatus, features of construction and combinations of parts of thecharacter hereinafter described and claimed.

For an illustration of some of the forms my invention may take,reference is to be had to the accompanying drawings in which:

Figure 1 is a vertical sectional view, partly in elevation, of apparatusconstructed in accordance with my invention.

Fig. 2 is a horizontal sectional view taken on the line 22 of Fig. 1 andlooking in the direction of the arrows.

Fig. 3 is a vertical sectional view, partly in elevation, of a systemfor cleaning pulp stock.

Fig. 4 is a plan view .of the system shown in Fi 3.

Referring to Figs. 1 and 2, B represents a base of any suitableconstruction carrying a housing or shell H which is secured to said baseB in any suitable or desired manner.

A shaft 1 disposed vertically and longitudinally of the housing Hcarries, adjacent its lower end, a member or hub 2, said shaft 1 andmember 2 being secured together in any suitable manner for rotativemovement together.

The member 2 supports a drum D of suitable corrosion-resisting metalwhich is secured thereto in any suitable manner for rotative movementtherewith, the member 2, preferably, comprising an outer circularvertical wall or flange for the reception of said drum D. The drum D,preferably, is circular in cross-sectional configuration and, inaccordance with my invention, is so formed as to define a plurality ofsteps, each of which is formed by the intersection of a verticalcylindrical wall portion 3 and a horizontal annular wall portion 4. Asillustrated particularly in Fig. 1, the drum D is of minimum diameter atits bottom and maximum diameter at its top. This is in accordance withmy invention as hereinafter particularly to be described.

The upper vertical wall of the drum D terminates in an outwardly anddownwardly disposed flange or shelf 5 utilizable as hereinafterdescribed.

In the form of my invention herein illustrated the drum D, at its top,carries a spider which comprises a suitable number of radial arms 6suitably secured at their outer ends to the upper vertical drum wall 3,said arms 6, preferably, being formed integrally with an outer hub 7connected by ribs 8 to an inner hub 9 coacting directly with the shaft1.

The hub 7 carries a conduit 10 preferably concentrically disposed withrespect to the shaft 1, said conduit 10, by preference, terminating in aflaring nozzle 10a, the lower surface of which is spaced from the lowerwall of the drum D. If desired, there may be an upwardly extendingsleeve 11 of suitable corrosion-resisting metal and closely embracingthe shaft 1.

Carried by the housing H is a cap structure C, bolts 12, or anequivalent arrangement, being utilized to retain the cap C on saidhousing H.

The cap C has secured thereto in any suitable manner an annular trough13, the inner wall of which is disposed beneath the aforesaid flange orshelf 5 at the top of drum D. At a suitable level, an opening is formedin housing H, such opening being in communication with the trough C andbeing disposed in alinement with a tangential outlet conduit 14 boltedor otherwise suitably secured to the exterior surface of the hous- Thecap member C is provided with an opening through which an inlet conduit15 extends, said conduit 15 being suitably secured to the cap member Cand having an outlet throat opening toward the aforesaid conduit 10.

The shaft 1 may be rotated in any suitable or desired manner. As hereinillustrated although not necessarily, said shaft 1 is rotated by asuitable electrical motor M carried by the aforesaid cap member C,coupling members 16, 16 being utilized to connect the motor shaft to theshaft 1. Where the shaft 1 is supported in anti-friction bearingstructures, as it usually is, one of such bearing structures may bedisposed in and carried by the cap member C at the upper end of shaft 1while another of such bearing structures may be disposed within a casingformed and the upper wall of base B are provided with openings 18. Thelatter open into a funnelshaped member 19 having a discharge conduitleading to any suitable destination, not shown.

The operation of the apparatus shown in Figs.

1 and 2 is as follows:

The motor M is energized to such extent that the drum D rotates atsuitable speed such, for example, as with a peripheral velocity of 100ft. per second, or less.

A mixture of the pulp stock and water is then introduced into theconduit 15 and passes downwardly first between the rotating hubs l and9, then through the rotating conduit 10 and emerges from the latterthrough the rotating nozzle 10a. From the latter, the aforesaid mixture,under the influence of centrifugal action, is thrown against the lowestvertical drum wall 3.

The pulp stock and water mixture should be introduced continuously andat a substantially regular rate through the conduit 15, the new supplythus being introduced as it is thrown against said lowest drum wall 3causing the previously admitted mixture to mount higher and higher alongthe drum wall D. In so doing, the mixture ascends a vertical wall 3,then passes laterally immediately above a horizontal wall 4 and intoengagement with the next upper vertical wall 3. From the uppermostvertical wall 3, the mixtures passes over the shelf 5 and enters thetrough 13 from which it escapes by way of the discharge conduit 14.

The pulp stock and water mixture, as it thus ascends along the side wallstructure of drum D, forms vertical layers along each of the verticaldrum walls 5, such layers being of relatively small thickness and beingdetermined, approximately, .by the rate at which the mixture is suppliedthrough the conduit 15.

Accordingly, thepulp stock and water mixture progressively ascend thedrum vertical walls 3 and, as such mixture reaches the top of each, itis thrown into contact with the next higher vertical wall 3. By virtueof such action, there is a constant rubbing or grinding of the pulp Imixture both within itself and against the aforesaid drum walls wherebyany pulp stock or fibre bundles or masses are substantially orcompletely disintegrated. Moreover, as the pulp stock passessuccessively from zones of smaller diameter to zones of larger diameter,it is acted upon by centrifugal forces of increasing magnitude, due tothe increases of diameter of the drum from zone to zone. Thecircumference of the drum also increases from zone to zone so that thethin stream of stock becomes wider and wider, and hence thinner andthinner as it reaches successive zones. Furthermore, in passing fromzone to zone, the thin stream of stock is forced at high speed over theshoulders between the zones, namely, the surface defined by the junctionof a vertical wall 3 with a horizontal wall 4. This action last named ishighly advantageous because contributinglargely to the aforesaid fibrebundle or mass disintegration.

Due to the centrifugal action described above, the aforesaid mixturedoes not escape from the drum D by way of the openings 1'7. However,when operation of the apparatus is discontinued,

the material then in the escapes therefrom v by way of said openings 17,and then passes to the funnel-shaped member 19 by way of the openings18. From the member 19, the material passes to waste or other suitabledestination by way of the conduit 20.

Pulp stock destined for paper manufacture is'desirably treated inaccordance with my invention and, as a result, the formation of theresulting paper is improved as is the strength thereof. Moreover,bleaching of the pulp stock is better effected after the same has beensubjected to the action of the drum D.

The apparatus illustrated in Figs. 1 and 2 somewhat resembles thecentrifugal separator disclosed in Thomassen U. S. Letters Patent No.1,599,502, granted Sept. 14, 1926. With a construction such as disclosedin that patent, the pulp stock is purified because ofimpurity-entrapment by the rings 10. The latter, or an equivalentthereof, are not utilized in accordance with my invention and, as aresult, the impurities largely pass along with the pulp mixture.However, since the rings 10 of said patent, or equivalent, are notutilized, the desirable result of my invention is attained as describedabove.

Referring to the form of my invention illustrated in Figs. 3 and 4, themixture of the pulp stock and water is shown as traversing a channel 25and entering a knotter or screen A of a character well known to the art,the latter comprising the usual rotatable drum 27 driven in any suitablemanner, as by the pulley 28.

From the knotter or screen A, the aforesaid mixture is passed to andthrough the conduit 15 of the apparatus shown in-Figs. 1 and 2 whichfunctions as hereinbefore described to substantially or completelydisintegrate any fibre bundles.

Eventually, the pulp stock and water mixture passes, by way of theconduit 14, into any suitable cleaning device S which may be aconventional rifiieror sand trap. In the latter, grains of sand andother impurities are separated from the-aforesaid mixture, the purifiedpulp stock 31% passing along a channel 29 to any suitable destination.

A pulp stock treating system of the character shown in Figs. 3 and 4involves, as stated, a drum D especially designed to eifect separationand disintegration of the fibre bundles. By virtue of this action,foreign substances are readily separated from the pulp stock in thecleaning device S.

An arrangement of the character illustrated in Figs. 3 and 4 isespecially desirable and suitable for treating cellulose or wood pulp.However, it shall be understood that the invention of Figs. 3 and 4 isnot to be limited to treatment of pulp stock of the character justdescribed.

It shall also be understood that the apparatus shown in Figs. 1 and 2 isby no means at all to be limited to association with a system such asshown in Figs. 3 and 4 although said system does illustrate oneimportant application for M0 the apparatus of Figs. 1 and 2.

While the invention has been described with respect to certainparticular preferred examples which give satisfactory results, it willbe understood by those skilled in the art after understanding theinvention, that various changes and modifications may be made withoutdeparting from the spirit and scope of the invention and it is intendedtherefore in the appended claims to cover all such changes andmodifications. 1159 What I claim as new and desire to be secured I byLetters Patent is:

1. In the art of treating pulpstock, the method which comprisessupplying a mixture of pulp stock and water to a rotating chamber havingan inner surface defining a series of steps, the pulp stock andsubstantially all impurities therein passing in a thin stream along andrubbing against the walls of said steps and aroundithe corners thereofwhereby any bundles of pulp stock are subjected to abundle-disintegrating action.

2. In the art of treating pulp stock, the method which comprises passingamixture of pulp stock and water in a thin stream over alternatecylindrical and annular wall segments of a rotating chamber whereby anybundles of pulp stock are subjected to a bundle-disintegrating action,and thereafter passing the mixture of pulp stock and water to animpurity-removing device.

4. In the art of treating pulp stock, the method which comprises flowingthe stock rapidly in a thin stream over a hard surface, subjecting thethin stream to strong centrifugal force to rub the stock therein againstsaid hard surface.

5. In the art of treating pulp stock, the method which comprises flowingthe stock rapidly in a thin stream over a hard surface, subjecting thethin stream to strong centrifugal force to rub the stock therein againstsaid hard surface, and progressively increasing the thinness. of saidstream and the magnitude of the centrifugal force acting thereon.

' GUMAL KNOPP.

